Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/103344
Title: Can the state of platinum species be unambiguously determined by the stretching frequency of adsorbed CO probe molecule?
Author: Aleksandrov, Hristiyan A.
Neyman, Konstantin M.
Hadjiivanov, Konstantin I.
Vayssilov, Georgi N.
Keywords: Metalls de transició
Catàlisi
Platí
Adsorció
Transition metals
Catalysis
Platinum
Adsorption
Issue Date: 13-Jul-2016
Publisher: Royal Society of Chemistry
Abstract: The paper addresses possible ambiguities in the determination of the state of platinum species by the stretching frequency of a CO probe, which is a common technique for characterization of platinum-containing catalytic systems. We present a comprehensive comparison of the available experimental data with our theoretical modeling (density functional) results of pertinent systems - platinum surfaces, nanoparticles and clusters as well as reduced or oxidized platinum moieties on a ceria support. Our results for CO adsorbed on-top on metallic Pt0, with C-O vibrational frequencies in the region 2018-2077 cm−1, suggest that a decrease of the coordination number of the platinum atom, to which CO is bound, by one lowers the CO frequency by about 7 cm−1. This trend corroborates the Kappers-van der Maas correlation derived from the analysis of the experimental stretching frequency of CO adsorbed on platinum-containing samples on different supports. We also analyzed the effect of the charge of platinum species on the CO frequency. Based on the calculated vibrational frequencies of CO in various model systems, we concluded that the actual state of the platinum species may be mistaken based only on the measured value of the C-O vibrational frequency due to overlapping regions of frequencies corresponding to different types of species. In order to identify the actual state of platinum species one has to combine this powerful technique with other approaches.
Note: Versió postprint del document publicat a: https://doi.org/10.1039/C6CP03988J
It is part of: Physical Chemistry Chemical Physics, 2016, vol. 18, p. 22108-22121
URI: http://hdl.handle.net/2445/103344
ISSN: 1463-9076
Appears in Collections:Articles publicats en revistes (Ciència dels Materials i Química Física)
Publicacions de projectes de recerca finançats per la UE

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